Jenkins wowed the crowd with his rapid-fire defenses of Wikipedia, Second Life, YouTube and much of the other innovations that have swept the tech world in recent years. (And in true gentlemanly fashion, he then posted links to blog posts that he referred to in the talk.)

He called Wikipedia “a monument to participatory culture. To see the history pages on those entries is to see the struggles and debates that took place. I had so much respect for the Encyclopedia Britannica until I was asked to write an entry for it. I’m only one person!”

Part of Jenkins’ brilliance lay in his ability to relate these distinctively 21st century phenomena with their historical antecedents. He compared people falling for Lonelygirl15, the YouTube hoax, with people in an earlier century. Back then, when scientists in Australia said they found a furry creature with a duck bill that laid eggs, no one was sure if it was true. P.T. Barnum exploited that with sideshows that argued, “The status of this is under dispute. Come to decide for yourself if it’s true or not.”

As for the virtual world in Second Life, Jenkins first noted that “my avatar is now my ideal weight. Television puts 10 pounds on you and Second Life takes 20 off.”

But that’s not its only benefit. “It’s a new center of participatory culture,” he said. “I compare it to the medieval carnival, where people stepped out of their roles. Women dressed as men and beat the men who were abusive to their wives.”

We should use Second Life for similar experiments, he said. “What cultural transformations could take place as we try new ideas out? We could carry that energy back out into the real world with us,” he said. “What about a virtual Palestine? We could create a common space online. Those are the things Second Life could give us if we think of it as a place for social experimentation that has an impact on the real world, and not about using Second Life as a fantasy way of escaping first life.”